1. Field of the Invention
The invention relates in general to a laser projection device and a method for manipulating the same, and more particularly to a laser projection device modulating image resolution according to a projection distance and a method for manipulating the same.
2. Description of the Related Art
The integration of various functions and applications on portable electronic device (such as mobile phone) has become a mainstream trend in the research and development of the industries. Integrated projection system (such as micro-projection system) can be used for projecting frame message (such as films and web-pages) for user's portable application as well as social activities such as conference and video call.
The laser projection system depends on a collimated laser source, which performs scanning along with the time to generate image frames. As the projection distance varies, the size of light spots projected on a projection screen changes accordingly. The projection angle of the laser source does not vary with the projection distance. When the projection distance is reduced, the area of the projection image projected on the projection screen is reduced accordingly. Because the resolution of projection image remains unchanged and the same quantity of projection pixels projected on an area-reduced projection image, the ratio of the light spots projected on the projection screen with respect to the size of the pixels will become larger and the light spots will overlap with each other. Consequently, the color of image frame is distorted, the color saturation of projection image is reduced and the display quality is affected.